// 侧导航栏
.shell{
  position: absolute;
  z-index: 9;
  top: 0;
  left: 0;
  width: 100px;
  height: 700px;
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
  background-color: rgb(17, 24, 39);
  border-radius: 10px;
  transition: 0.3s;
  overflow: hidden;
  .box{
    display: block;
    height: 15%;
    width: 85%;
    margin: 9px;
    border-radius: 5px;
    position: relative;
    transition: 0.3s;
    color: rgb(160, 160, 175);
    i{
      font-size: 60px;
      position: absolute;
      margin: 7px 0 0 13px;
    }
    span{
      position: relative;
      top: 22px;
      left: 80px;
      font: 500 20px "";
      opacity: 0;
      transition: 0.1s;
    }
  }
  .box:nth-child(1)::before,
  .box:nth-child(5)::before {
    content: "";
    display: block;
    width: 100%;
    height: 2px;
    background-color: rgb(55, 65, 81);
    position: absolute;
    bottom: -10px;
  }
  .box:hover {
    color: #fff;
  }
}
.shell:hover {
  width: 270px;
}
.box:hover {
  background-color: rgb(55, 65, 81);
}
.shell:hover span {
  opacity: 1;
}